Another feature growing in prominence is the use of LEDs as backlights for LCD TV panels. Both Samsung and Toshiba call their models with this feature "LED TVs," which has confused many consumers. LED TVs are not a new technology; they're just LCD TVs with a different type of backlight. LEDs have some distinct advantages over traditional cold-cathode fluorescent lamp (CCFL) designs, which many LCD TVs use. Compared with CCFL technology, LED backlighting results in TVs that require less power (by up to 40 percent for a 40-inch television) and provide improved color performance: LED TVs handle red and green hues better, resulting in more-natural, more-lifelike picture quality.
Perhaps the foremost advantage of LED backlighting is its ability to enhance contrast and produce darker blacks. This capability closes the gap between LCD screens and plasma displays, which traditionally have offered deeper blacks than LCDs. Here again, manufacturers have adopted two different approaches to implementing LED backlights. One design puts the LED lights behind the LCD panel in a big matrix layout. This approach permits the use of "local dimming": If the controller recognizes that a portion of the image is generally dark, it can automatically dim the LEDs behind that one small segment of the image. This helps keep black levels low, increasing the apparent contrast.
The other way to use LEDs with LCD panels is to put them along the edge behind the panel, as Samsung's 1.2-inch-thick, 46-inch UN46B8000 does. This approach requires sophisticated diffusers to spread the light evenly behind the LCD layer, and it reduces or eliminates the ability to improve apparent contrast through localized, content-based dimming. It does keep the part count much lower, however, and it can make the heat that the LEDs generate easier to manage.
Though LEDs have their benefits, they come with their own issues. For one thing, LED TVs cost appreciably more than CCFL-based models--about $300 more, on average--due both to the cost of manufacturing the LEDs and to the cost of installing these arrays. Also, LED production processes cannot yet make units with consistent color output, so manufacturers must inspect each LED and "bin" it--grouping it with other LEDs of similar color. The more consistent and accurate the color output required, the more the individual LEDs cost. Until the industry solves this problem, LCD TVs with LED backlights are likely to cost more than CCFL sets.
If you care about color quality and are willing to tweak your television, an LED-backlight model may be worth the extra money. Even at a $300 premium, you would be paying less than $30 a year extra over the set's expected lifetime, or less than $2.50 a month. We've seen some lovely images produced by LED-backlit HDTVs--on the Samsung LN-A950, for example. Note, however, that none of the models we tested for this roundup included LED backlights.
Another big trend this year involves connections to bring the Internet to your TV. Many HDTVs have an ethernet connection on the back, plus integrated software for dealing with Web content. If you connect to the Internet via your home network's router, your TV can gain access to a range of Web-based content, all without going through a computer.
According to data from Nielsen, 90 percent of U.S. homes now have access to broadband Internet connections, so the connected TV is entirely feasible with today's technology, especially if the HDTV set has a Wi-Fi capability, as many do.
The TVs shipping today that have Web access limit the locations you can visit online. This approach simplifies navigation, which is important because you have to use a remote control instead of a keyboard, mouse, and full-on Web browser.
This year marks the debut of Yahoo Connected TV's Widgets; the Widgets are now offered on Internet-capable sets from LG, Samsung, Sony, and Vizio. The services and presentation vary from one brand to another, as manufacturers make different choices about which Widgets to offer. Widgets are available for news, weather, and sports information, as well as for access to popular sites like YouTube, Twitter, Flickr, and Facebook.
Yahoo Widgets isn't the only Internet connectivity going. Sony has continued to develop its Bravia Internet Video Link version of streaming, Web-based content--which includes modules for Amazon Video on Demand, CBS, Netflix, Slacker Internet Radio, YouTube, and more. Other sets, such as units developed by Panasonic and by LG Electronics, have modules for services as well; the most popular inclusions are Amazon Video on Demand, Netflix and Vudu, along with photo sharing sites such as Flickr and Picasa, and streaming music Websites like Pandora and Slacker Internet Radio.
Network connectivity can give you access to the content you've stored on your home network, including CDs you've ripped, digital photos, and digital home movies. Some sets can access those items, as well. The Digital Living Network Alliance certifies most connected TVs; put your files on a DLNA-certified storage device on your network, and a DLNA television will be able to play your music and screen your photos and videos. According to the Alliance's Website (www.dlna.org) more than 500 DLNA-certified television models are available. Windows Media Player 11 and 12 are DLNA servers too, so using a PC that runs XP, Vista, or Windows 7 will work, if you use WMP 11 or 12 for your media library.
Integrated ethernet has another advantage: Upgrades to your television's software can download automatically, so the updated firmware, or a new Widget or other service, will be available the next time you turn on your HDTV.
Network connectivity will give you access to an enormous amount of additional content--much of it on-demand and free--but do some research before plunking down your cash if you want specific services or capabilities. Having an ethernet connection doesn't automatically mean that an HDTV will stream media through your home network, or have all the Web services you seek.